Tuesday, 29 May 2018

An article
published this year in “Journal of
International Natural Products” using one of our products,“FITC Apoptosis
Detection Kit”, by our customers fromtheCRIOBE,
USR CNRS-EPHE-UPVD, Universitéde Perpignan, France and Universidad de Santiago
de Compostela, Lugo, Spain in how Structures
and Activities of Tiahuramides A−C, Cyclic Depsipeptides from a Tahitian
Collection of the Marine Cyanobacterium Lyngbya majuscula. Congrats and
Thanks.

Summay:

The structures of three new cyclic depsipeptides, tiahuramides A (1), B
(2), and C (3), from a French Polynesian collection of the marine
cyanobacterium Lyngbya majuscula are described. The planar structures of these
compounds were established by a combination of mass spectrometry and 1D and 2D
NMR experiments. Absolute configurations of natural and nonproteinogenic amino
acids were determined through a combination of acid hydrolysis, derivitization
with Marfey’s reagent, and HPLC. The absolute configuration of hydroxy acids
was confirmed by Mosher’s method. The antibacterial activities of tiahuramides
against three marine bacteria were evaluated. Compound 3 was the most active
compound of the series, with an MIC of 6.7 μM on one of
the three tested bacteria. The three peptides inhibit the first cell division
of sea urchin fertilized eggs with IC50 values in the range from 3.9 to 11 μM. Tiahuramide B (2), the most potent compound, causes cellular
alteration characteristics of apoptotic cells, blebbing, DNA condensation, and
fragmentation, already at the first egg cleavage. The cytotoxic activity of
compounds 1−3 was tested in SH-SY5Y human neuroblastoma cells. Compounds 2 and
3 showed an IC50 of 14 and 6.0 μM, respectively,
whereas compound 1 displayed no toxicity in this cell line at 100 μM. To determine the type of cell death induced by tiahuramide C (3),
SH-SY5Y cells were costained with annexin V−FITC and propidium iodide and
analyzed by flow cytometry. The double staining indicated that the cytotoxicity
of compound 3 in this cell line is produced by necrosis.